Stoneware is a coarse, glazed, and fired potter's ceramic that is used to make crocks, jugs, bowls, etc. It is often decorated with cobalt blue decorations. In the nineteenth and early twentieth centuries, potters often decorated crocks with blue numbers indicating the size of the container. A "2" meant 2 gallons. Other decorations were birds, trees, and sketches drawn with a blue line. Stoneware is still being made. American stoneware is listed here.